CZ20002581A3 - Metal catalyst, process for its production and its use - Google Patents

Abstract

Raney type metal catalysts are made of hollow bodies, e.g. spheres. The method of their production consists in that the metal powder together with a binder is sprayed onto bodies of suitable shape made of combustible material, e.g. polystyrene, the combustion of which produces a hollow body of the metal catalyst. The use of these catalysts is for hydrogenation, dehydrogenation, isomerization, reductive alkylation, reductive amination and/or hydration of organic compounds.

Description

The present invention relates to metal catalysts.

State of the art

Activated metal catalysts are known in the field of chemical engineering as Raney catalysts. They are used, on a large scale in powder form, for numerous hydrogenations, dehydrogenations, isomerizations and hydrations of organic compounds. These powder catalysts are made from an alloy of a catalytically active metal, also referred to herein as the catalyst metal, with another alloying component, soluble in alkalis. The catalyst metals used are mainly nickel, cobalt, copper or iron. Aluminum is usually used as the alloying component, which is soluble in alkalis, but other components, in particular zinc and silicon or mixtures thereof with aluminum, can also be used.

These so-called Raney alloys are generally produced by ingot casting. In this process, a mixture of catalyst metal and, for example, aluminum is first melted and then cast into ingots. Typical alloy charges on an industrial scale are about 10 to 100 kg per ingot. According to DE 21 59 736, cooling times are up to 2 hours. This corresponds to an average cooling rate of about 0.2/s. In contrast, in processes where rapid cooling is used (for example, the spray method), rates of 102 to 106 K/s are achieved. The cooling rate is influenced in particular by the particle size and the cooling medium (cf.

• ·

Materialwissenschaft und -technologie, editors R.W.Chan, P.Haasen, E.J.Kramer, vol. 15, Verarbeitung von Metallen und Legierungen, 1991 VCH-Verlag Weinheim, pp. 57 to 110). A process of this type is used according to EP 0 437 788 for the production of Raney alloy powder. In this process, the molten alloy is atomized at a temperature of 50 to 500 °C above its melting point and cooled with the aid of water and/or gas.

To produce the catalyst, the Raney alloy, if not produced in the desired powder form, is first finely ground. The aluminum is then completely or partially extracted with alkalis, such as caustic soda. This activates the alloy powder. After the aluminum is extracted, the alloy powder has a high specific surface area (BET value) of 20 to 100 m ² /g, and is rich in active hydrogen. The activated catalyst powder is pyrophoric and is stored under water or organic solvents, or in organic compounds that are solid at room temperature.

Powder catalysts have the disadvantage that they can only be used in a discontinuous process and after the catalytic conversion they must be separated from the reaction medium by costly settling and/or filtration. Therefore, many methods have been described for the production of shaped bodies which, after extraction of the aluminium, lead to activated metal catalysts in a fixed bed. In this way, it is possible to obtain, for example, coarse-grained Raney alloys, i.e. Raney alloys which are only coarsely ground and which can be activated by treatment with caustic soda. The extraction and activation then takes place only in the surface layer, the thickness of which can be adjusted by the conditions used in the extraction.

A significant disadvantage of catalysts produced in this way according to the prior art is the low mechanical stability of the activated outer layer. Since only this outer layer of the catalyst is catalytically active, abrasion leads to rapid deactivation, and repeated activation of the deeper alloy layers with caustic soda then leads to partial reactivation at best.

Patent application EP 0 648 534 describes a shaped activated Raney metal catalyst in a fixed bed and a method for its production. These catalysts eliminate the above-mentioned disadvantages, such as the poor mechanical stability resulting from the activation of the outer layer. For the production of these catalysts, a mixture of catalyst alloy powders and a binder is used, each of the catalyst alloys containing at least one catalytically active catalyst metal and an extractable alloy-forming component. Pure catalyst metals or mixtures thereof which do not contain extractable components are used as the binder. The use of a binder in an amount of 0.5 to 20% by weight, based on the catalyst alloy, is essential to achieve sufficient mechanical strength after activation. After shaping the catalyst alloy and the binder with conventional shaping and pore-forming agents, the freshly produced shaped bodies obtained are calcined at temperatures below 850 °C. As a result of the sintering process in a finely divided binder, solid compounds are obtained between the individual catalyst alloy granules. These compounds, in contrast to catalyst alloys, are not or are only slightly extractable, so that a mechanically stable structure is obtained even after activation. However, the added binder has the disadvantage that it is essentially catalytically inactive; as a result, the number of active centers in the activated layer is reduced. In addition, the absolutely essential use of the binder means that only a limited amount of pore-forming agents can be used without compromising the strength of the shaped body. For this reason, the bulk density of these catalysts cannot be reduced to a value of less than 1.9 kg per liter without loss of strength. This leads to a considerable economic disadvantage when these catalysts are used in an industrial process. Especially when expensive catalyst alloys, such as cobalt alloys, are used, the high bulk density leads to high costs for the reactor bed, which is partly offset by the high activity and long-term stability of these catalysts. In certain cases, the high bulk density of the catalyst requires a mechanically reinforced reactor design.

The essence of the invention

The object of the present invention is therefore to provide activated base metal catalysts from metal hollow bodies, largely free from the disadvantages of the known fixed bed catalysts mentioned.

The above and other objects of the present invention are achieved by forming hollow shapes from the desired alloys and activating them to obtain a catalyst. The main advantages of the present invention are the low bulk density and the high activity that these materials exhibit per gram of metal.

The present invention relates to metal catalysts comprising hollow shapes. Preferably, these hollow shapes are hollow spheres. These spheres may have a diameter of 0.5 to 20 mm and a wall thickness of 0.1 to 5 mm.

The shell of the ball may be impermeable or may exhibit

* • 9

9> ··

open porosity up to 80%. The shell of the ball may consist of different layers and/or the metal may be graded.

Metal catalysts comprising hollow bodies can be activated.

Another subject of the invention is a method for producing metal catalysts, comprising spraying metal powders, optionally together with a binder, onto shapes consisting of a combustible material, e.g. expanded polystyrene, and burning this material to obtain a hollow body.

In another embodiment of the process for producing metal catalysts according to the invention, one of the metal powders consists of a rapidly cooled alloy. The rapidly cooled alloy can be formed by conventional methods, such as spray drying in various atmospheres, as well as by rapid cooling in liquids, such as water. The hollow shape consisting of the alloy and optionally a binder can then be activated with alkaline solutions, such as caustic soda, to form an activated catalyst.

One of the metal powders may consist of a slowly cooled alloy. The hollow shape consisting of the alloy and optionally a binder may then be activated with an alkaline solution, such as caustic soda, to form an activated catalyst.

In the process for producing metal catalysts, the alloy may consist of one or more catalytic metals, e.g.

of nickel, iron, copper, palladium, ruthenium and cobalt; alkali-soluble components such as aluminum, zinc and silica; and optionally one or more promoter elements such as Cr, Fe, Ti, V, Ta, Mo, Mg, Co and/or W.

The hollow spheres according to the invention can be produced according to Andersen, Schneider, Stephani: Neue Hochporóse Metallische Werkstoffe (Ingenieur-Werkstoffe, 4, 1998, pp. 36-38). In this method, a mixture of the desired alloy, an organic binder and optionally an inorganic binder is simultaneously sprayed into a fluidized bed of polystyrene spheres, where it coats the spheres. The coated spheres are then calcined at selectable temperatures in the range of 450 to 1000 °C to burn out the polystyrene due to the high calcination temperature, to sinter the metal and to stabilize the hollow shapes. After calcination, the catalyst is activated with caustic soda to obtain an activated catalyst from the parent metal. Another advantage of this catalyst system is that the wall thickness of the hollow shapes can be easily controlled by the coating conditions and the wall porosity by the particle size and composition of the original powder wall.

For highly active catalysts, the bulk density of the resulting fixed bed catalyst is very important. While known activated standard metal-based fixed bed catalysts exhibit bulk densities in the range of 2.4 to 1.8 kg/liter, bulk densities of e.g. 0.3 to 1.0 kg/liter are largely required for other fixed bed applications in order to keep the cost of commercial reactor loading to a minimum.

The weight ratio of catalyst metal to extractable alloying component in the catalyst alloy is, as is customary for Raney alloys, in the range of 20:80 to 80:20. The catalysts according to the invention can also be doped with other metals having an effect on the catalytic properties. The purpose of this type of doping is, for example, to improve the selectivity in « * • · · • · · · special reactions. Doping metals are often referred to as promoters. Doping of Raney catalysts or the use of promoters is described, for example, in US Patent 4,153,578, DE-AS 21 01 855, DE-OS 21 00 373 and DE-AS 20 53 799.

In principle, any known metal alloy can be used, such as nickel-aluminum, cobalt-aluminum, copper-aluminum, nickel-chromium, iron-aluminum. Thus, any Raney-type alloy can be used in which there is a combination of leachable materials, such as zinc, silicon and/or aluminum, together with catalytic materials, such as nickel, cobalt, copper and/or iron.

The alloys may contain doping materials such as chromium, iron, titanium, vanadium, tantalum; extractable elements such as aluminum, zinc and silicon may be used according to the invention. Suitable promoters are transition elements in groups IIIB to VIIB and VIII as well as group IB of the periodic table of the elements, and also rare earth metals. They are used in amounts of up to 20% by weight, based on the total weight of the catalyst. Chromium, manganese, iron, cobalt, vanadium, tantalum, titanium, tungsten and/or molybdenum, as well as metals of the platinum group, are used as promoters. They are expediently added to the catalyst alloy as alloying components. Furthermore, the promoters may be used in the form of a separable metal powder or may be applied to the catalyst material at a later stage. The promoters may be applied later either after calcination or after activation. This allows for optimum adjustment of the catalyst properties for specific catalytic processes.

The precursors of the Raney-type catalyst resulting from calcination are, in terms of the effectiveness of the invention • 9 0 · *

0« • 0 9

Η·· ♦ ♦

00 is also very important. They are not pyrophoric and can be handled and transported without difficulty. Activation can be carried out by the user shortly before use. Storage under water or organic solvents or embedding in organic compounds is not necessary for catalyst precursors.

The metal catalysts of the invention can be used for the hydrogenation, dehydrogenation and/or hydration of organic compounds.

Examples of embodiments of the invention

Comparative example 1

According to the recipes in EP 0 648 534, a free-flowing pelletizable catalyst mixture was produced for a comparative catalyst consisting of 1000 g of a powder alloy of 53% Ni and 47% Al, 100 g of pure nickel powder (99% nickel, d50 = 21 μπι) and 25 g of ethylenebisstearoylamide, with the addition of about 150 g of water. Tablets with a diameter of 4 mm and a thickness of 4 mm were pressed from this mixture. The shaped bodies were calcined for two hours at 700 °C. After calcination, the tablets were activated with 20% sodium hydroxide solution for 2 hours at 80 °C. Under the conditions of the application example, the hydrogenation of nitrobenzene began at 120 °C, and the activity was 1.36 ml of hydrogen consumed per gram of catalyst per minute.

Example 1

The coating solution was prepared by suspending 600 g of rapidly cooled alloy of 50% Ni and 50% Al in 800 ml

9 9 •99 · • 99 • 9 · • · *

99·· ··

99 99 99 • 99 9 9 99 9

9 99 9 9 9 9

99 9 99 99 9 ♦ 9 9 9 9 99 9

99 99 9· aqueous solution containing 5% by weight of polyvinyl alcohol and

1.25 wt. % glycerin. This suspension was then sprayed onto 1500 ml of 4-5 mm polystyrene foam beads, which were suspended in an upward air stream. After coating the beads with the above solution, the beads were dried in an upward air stream at temperatures up to 80 °C (higher temperatures can also be used). These dried, coated polystyrene beads had a bulk density of 0.45 g/ml; half of these beads were further coated with an alloy solution to demonstrate the flexibility of the process. The solution for the second layer consisted of 700 g of a rapidly cooled 50% Ni and 50% Al alloy, which was suspended in 800 ml of an aqueous solution containing 5 wt. % polyvinyl alcohol and 1.25 wt. % glycerin. This suspension was sprayed onto 750 ml of the above-mentioned, Ni/Al alloy pre-coated and dried polystyrene beads, which were suspended in an upward air stream. After coating the polystyrene beads with the above solution, the beads were dried in an upward air stream at temperatures up to 80 °C (higher temperatures can also be used). Although the solution for the second layer was similar to the first, this technique demonstrates the suitability of the present method for producing coated hollow beads. The dried coated beads were then heated in a controlled nitrogen or air stream for one hour at 83 0 °C to burn out the polystyrene and sinter the alloy particles. The hollow beads were then activated with 20% (w/w) sodium hydroxide solution for 1.5 hours at 80 °C after calcination. The obtained activated hollow spheres had a diameter in the range of 5 to 6 mm, a shell thickness of 700 to 1000 μιη, a compressive strength of 90 N and a bulk density of 0.62 g/ml. Under the conditions of Application Example 1, the hydrogenation of nitrobenzene started at 110 to 120 °C, and the activity of the catalyst on nitrobenzene was 1.54 ml of hydrogen consumed per gram « ·

44

4

4 ♦ 4 • 44

444 44 4*4 44 4 • 4 4 · 4 9 4 * 4 4 4

4444 4* 44 44 44 44 catalyst per minute.

Example 2

A coating solution was prepared by suspending 500 g of a rapidly cooled 50% Ni and 50% Al alloy together with 37.5 g of nickel powder in 750 ml of an aqueous solution containing 5% by weight polyvinyl alcohol and 1.25% by weight glycerin. This suspension was then sprayed onto 1000 ml of 4-5 mm polystyrene beads suspended in an upward air stream. After coating the polystyrene beads with the above solution, the beads were dried in upward air at temperatures up to 80 °C (higher temperatures can also be used). These dried, coated beads were heated in a controlled nitrogen or air stream for one hour at 840 °C to burn out the polystyrene and sinter the nickel and alloy particles. The hollow spheres were then activated with 20% (by weight) sodium hydroxide solution for 1.5 hours at 80°C. The activated hollow spheres obtained had a diameter in the range of 5 to 6 mm, an average shell thickness of 500 μm and a bulk density of 0.34 g/ml. Under the conditions of Application Example 1, this catalyst started to hydrogenate

nitrobenzene at 110 to 120 °C, and activity catalyst on nitrobenzene was 1.82 ml consumed hydrogen per gram of catalyst per minute. Example 3 It was made by coating solution by suspending 800g 50% Co and 50% Al alloys Al in 1000 ml water solution

with a content of 5% by weight polyvinyl alcohol and 1.25% by weight

glycerin.

t φφφ • φφφ * φ φ * φφ φφ

This suspension was then sprayed onto 2000 ml of polystyrene beads of 4 to 5 mm size, which were suspended in an upward air stream. After coating the polystyrene beads with the above solution, the beads were dried in an upward air stream at temperatures up to 80°C (higher temperatures can also be used). These dried, coated polystyrene beads had a bulk density of 0.35 g/ml, and half of these beads were further coated with an alloy solution. The solution for the second layer consisted of 800 g of a rapidly cooled alloy of 50% Co and 50% Al, which was suspended in 1000 ml of an aqueous solution containing 5% by weight polyvinyl alcohol and 1.25% by weight glycerin. This suspension was then sprayed onto 1000 ml of the above-mentioned, Co/Al alloy pre-coated and dried polystyrene beads, which were suspended in an upward air stream. After coating the polystyrene beads with the above solution, the beads were dried in an upward air stream at temperatures up to 80 °C (higher temperatures can also be used). The dried coated beads were then heated in a controlled nitrogen or air stream for one hour at 700 °C to burn out the polystyrene and sinter the alloy particles. The hollow beads were then activated with 20% (by weight) sodium hydroxide solution for 1.5 hours at 80 °C. The activated hollow beads obtained had a diameter in the range of 5 to 6 mm, a shell thickness of 700 μιυ, a compressive strength of 71 N and a bulk density of 0.50 g/ml. As was visually observable from the development of hydrogen bubbles, the catalyst had a large reservoir of active hydrogen.

Example 4

By suspending 800 g of an alloy of 50% Cu and 50% Al together with 104 g of copper powder in 1000 ml of an aqueous solution containing 5 ti ·· ·· 00 ·· ··

00 0 0 0 * 0 0 0 0 ·

00 · 0 00 ···· • 0 000 90 900 00 0

09 0090 0090

0000 90 00 00 ·· ·0 wt. % polyvinyl alcohol and 1.25 wt. % glycerine a coating solution was prepared. This suspension was then sprayed onto 2000 ml of polystyrene beads of size 4 to 5 mm, which were suspended in an upward air flow. After coating the polystyrene beads with the above solution, the beads were dried in upward air flow at temperatures up to 80 °C (higher temperatures can also be used). These dried, coated polystyrene beads had a bulk density of 0.26 g/ml, and half of these beads were further coated with an alloy solution. The solution for the second layer consisted of 800 g of an alloy of 50% Cu and 50% Al and 104 g of copper powder, which were suspended in 1000 ml of an aqueous solution containing 5 wt. % Cu. polyvinyl alcohol and 1.25 wt. % glycerin. This suspension was then sprayed onto 1000 ml of the above-mentioned, Co/Al alloy pre-coated and dried polystyrene beads, which were suspended in an upward air stream. After coating the polystyrene beads with the above solution, the beads were dried in upward air at temperatures up to 80 °C (higher temperatures can also be used). The dried coated beads were then heated in a controlled nitrogen or air stream at 550 °C to burn out the expanded polystyrene and sinter the copper and alloy particles.

Hollow balls then were then activated at 20% (by weight) caustic soda after time 1.5 hours at 80 °C. Acquired activated hollow balls had an average of 6 mm, fatty coats 600 to 700 μιη and bulk density 0.60 g/ml. How was it visually observable from the development of bubbles hydrogen, had catalyst large active oxygen reservoir.

Example 5

A coating solution was prepared by suspending 800 g slowly

44 *4 4 4 4 4 «4

4 4 4 · 4 4 4 44 4

44 44 4« «44«

4 4 44 44 444 44 4 • 44 4444 4444

444« 44 44 44 4« 44 cooled alloy of 50% Ni, 0.5% Fe, 1.2% Cr and 48.3% Al together with 60 g of nickel powder in 1000 ml of an aqueous solution containing 5% by weight polyvinyl alcohol and 1.25% by weight glycerin. This suspension was then sprayed onto 2000 ml of polystyrene beads of size 4 to 5 mm, which were suspended in an upward air flow. After coating the polystyrene beads with the above solution, the beads were dried in upward air flow at temperatures up to 80 °C (higher temperatures can also be used). These dried, coated polystyrene beads had a bulk density of 0.30 g/ml, and half of these beads were further coated with the alloy solution. The solution for the second layer consisted of 800 g of a slowly cooled alloy of 50% Ni, 0.5% Fe, 1.2% Cr and 48.3% Al and 60 g of nickel powder, which were suspended in 1000 ml of an aqueous solution containing 5% by weight polyvinyl alcohol and 1.25% by weight glycerin. This suspension was then sprayed onto 1000 ml of the above-mentioned, Ni/Fe/Cr/Al alloy pre-coated and dried polystyrene beads, which were suspended in an upward air stream. After coating the polystyrene beads with the above-mentioned solution, the beads were dried in upward air at temperatures up to 80 °C (higher temperatures can also be used). The dried coated spheres were then heated in a controlled nitrogen or air stream at 700°C to burn out the expanded polystyrene and sinter the nickel and alloy particles. The hollow spheres were then activated with 20% (by weight) sodium hydroxide solution for 1.5 hours at 80°C. The activated hollow spheres obtained had a mean diameter of 5.9 mm, a shell thickness of 700 μιη, a compressive strength of 85 N, and a bulk density of 0.55 g/ml. Under the conditions of Application Example 1, the hydrogenation of nitrobenzene using this catalyst started at 110°C, and the catalyst activity on nitrobenzene was 2.4 ml of hydrogen consumed per gram of catalyst per minute.

99 »9 • 9 9 · • 99

9«

9

9 9

9999 99

99

9 99

Example 6

A coating solution was prepared by suspending 1000 g of a rapidly cooled alloy of 50% Ni and 50% Al together with 75 g of nickel powder in 1000 ml of an aqueous solution containing 5% by weight polyvinyl alcohol and 1.25% by weight glycerin. This suspension was then sprayed onto 2000 ml of polystyrene beads of 2 to 3 mm size, which were suspended in an upward air stream. After coating the polystyrene beads with the above solution, the beads were dried in upward air at temperatures up to 80 °C (higher temperatures can also be used). These dried, coated polystyrene beads had a bulk density of 0.33 g/ml, and half of these beads were further coated with the alloy solution. The solution for the second layer consisted of 1000 g of a rapidly cooled alloy of 50% Ni and 50% Al and 75 g of nickel powder, which were suspended in 1000 ml of an aqueous solution containing 5% by weight polyvinyl alcohol and 1.25% by weight glycerin. This suspension was then sprayed onto 1000 ml of the above-mentioned, Ni/Al alloy pre-coated and dried polystyrene beads, which were suspended in an upward air flow. After coating the polystyrene beads with the above-mentioned solution, the beads were dried in upward air flow at temperatures up to 80 °C (higher temperatures can also be used). These dried, double-coated beads had a bulk density of 0.75 g/ml, and half of these beads were coated once more with a third addition of the alloy solution. The solution for the third layer consisted of 1000 g of a rapidly cooled alloy of 50% Ni and 50% Al and 75 g of nickel powder, which was suspended in 1000 ml of an aqueous solution containing 5% by weight polyvinyl alcohol and 1.25% by weight glycerin. This suspension

Φ φ φ · φ« φφ φφ φφ φφ φφ φ φφ φ φφ φ φφ φ φφ φ φφ φ φφ φ φφ φ • •ΦΦΦ · · φφφ φφ φφ φφ φφ φφφ φφφ • ΦΦΦ φφ φφ φφ φφ φφφ φφφ was then sprayed onto 500 ml of the above-mentioned, previously double-coated and dried polystyrene beads with the Ni/Al alloy. After coating the polystyrene beads with the above-mentioned solution, the beads were dried in upwardly flowing air at temperatures up to 80 °C (higher temperatures can also be used). The dried, triple-coated beads were then heated in a controlled nitrogen or air stream at 700 °C to burn out the polystyrene and sinter the nickel and alloy particles together. The hollow spheres were then activated in 20% (by weight) sodium hydroxide solution for 1.5 hours at 80°C. The activated hollow spheres obtained had a mean diameter of 4.5 mm, a shell thickness of 600 to 700 µm and a bulk density of 0.85 g/ml. Under the conditions of Application Example 1, the hydrogenation of nitrobenzene began at 78°C, and the activity of the catalyst for nitrobenzene was 3.46 ml of hydrogen consumed per gram of catalyst per minute.

Usage example 1

The catalytic activity of the catalyst according to Comparative Example 1 and Examples 1 to 5 in the hydrogenation of nitrobenzene was compared. For this purpose, 100 g of nitrobenzene and 100 g of ethanol were charged into a stirred autoclave with a volume of 0.5 liters, which was equipped with a gas stirrer. In the stirred autoclave, 10 g of the tested catalyst were suspended using a catalyst basket, so that the catalyst was well washed with the reaction mixture, and hydrogen was introduced. The hydrogenation was carried out at a hydrogen pressure of 40 bar and a temperature of 150 °C.

The initial temperature and hydrogen consumption rate were determined. The results are shown in Table 1. Samples were taken for the tests after 1, 2, 3, 4 and 5 hours and analyzed by gas chromatography.

·· ·· 99 fc· ·· ·· • fc · · * fc» · fc fcfc · fc fcfc fc · fcfc · fcfc ·

- 16 - >* « · ·*· «««·« ··»« ·· ·· ·· ·· ··

Table

JJ (C λ; JJ >Ί CO Λ Xi 0 <D 3 i—i _r Cj 4-J Ή K υ o tj £>Ί Cú 0 i—1 tí ω > ε 1.36 1.54 1.82 2.40 3.46 Initial temperature °C 125 1 110-120 110-120 110 78 Bundle weight kg/i 2.3 CN kO O 0.34 0.55 0.58 Inorganic binder Ni-powder 1 1 Ni-powder Ni-powder Ni-powder Promoters » 1 1 Cr, Fe 1 Active metal None None None None None Catalyst CE1 Electric OJ M E5 <0 ω

♦ » ··

Claims (12)

CLAIMS 1. Metal catalysts comprising hollow shapes. Metal catalysts according to claim 1, comprising hollow spheres. Metal catalysts according to claim 2 having a diameter of 0.5 to 20 mm and a wall thickness of 0.1 to 5 mm. The metal catalysts according to claim 2, having a sheath which is impermeable. The metal catalysts of claim 2, having a shell having an open porosity of at most about 80%. Metal catalysts according to claim 2, having a sheath consisting of different layers. Metal catalysts according to claim 2, having a casing which is graduated. A method for producing metal catalysts according to claim 1, comprising spraying metal powders, optionally together with a binder, on shapes that consist of a combustible material, such as polystyrene, and burning the material to obtain a hollow shape. A process for producing metal catalysts according to claims 5 and 8, wherein one of the metal powders consists of a rapidly cooled alloy. · · Tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit tit ·· ···· >> >> · ··· · v ·· ·· A process for producing metal catalysts according to claims 1 and 8, wherein one of the metal powders consists of a slowly cooled alloy. Method for producing metal catalysts according to claims 9 and 10, wherein the alloy consists of one or more catalytic metals such as nickel, iron, copper, palladium, ruthenium and cobalt; alkali soluble components such as aluminum, zinc and silica; and optionally one or more promoter elements such as Cr, Fe, Ti, V, Ta, Mo, Mg, Co and / or W. Use of the metal catalysts according to claim 1 for the hydrogenation, dehydrogenation, isomerization and / or hydration of organic compounds.